Fairing the deck edges (second ama)

We're just back from a business trip to San Francisco where we attended the American Geophysical Union Fall Assembly. Today I worked one hour to fair the deck edges of the second ama using mostly the power plane but also surforms and rasps. Here is how the second ama looks like now (after removing the sawdust all over the place)

We still have to fair the edges with sandpaper.

Total work time to date: 220 hours.

All glued (2nd ama)

Today is an holiday so we could spend two more hours to remove all the screws, glue the round pads to the deck, and fill all the screw holes. About 300 grams of resin were used.

Total work time to date: 219 hours

Second ama deck glued

Six hours this week end. We first cut the hatch hole on the deck panel.

We then faired the deck stringers on the hull with power plane, Surforms and sanding board, checking the planarity from time to time.

The round pads were faired and sanded, ready to be glued on the deck

At the end we glued the 12 mm deck (on which we had prebored the screw holes) on the hull, using 2.5 cm long screws on 15 cm centers. This required almost 1 kg of thickened resin. About 200 grams squeeze out from the joint on the outside and is cleaned right away, but probably the same amount squeezes out on the inside and will remain there forever since it's impossible to reach inside except around the hatch hole.

Total work time to date: 217 hours

Epoxy coating, butt blocks (2nd ama)

Two hours this evening to glue the deck butt blocks to the deck panels, and to give the first epoxy coating to the inner side of the deck. Tomorrow morning we'll give a second coat, and maybe we'll glue the deck.

Total work time to date: 211 hours

Cutting the deck (2nd ama)

Four hours this weekend, in which we scribed and cut the deck for the second ama, as well its butt blocks. We cut a 12 mm panel in two halves lengthwise, drilled the stud holes in the right place, and scribed the shape from underneath

We then cut the panel with the badass jigsaw

I also cut he two butt blocks (the distortion here is due to the perspective, luckily enough)

And here is the deck ready to glue

I also gave a first fairing to the deck stringers with the power plane.

Total work time to date: 209 hours

Coating the interior

Four hours in the last two days to give the ama interior two coats of resin, to glue the steel studs and the stem piece.

Here's a general view

Next will be fairing the deck stringers to get ready for glueing the deck panels.

Total work time to date: 205 hours

Here we go again (second ama)

During the past week Cinzia worked a couple of hours to fair the first ama hull.This morning we swapped the two amas: the first one, done, has been put aside on sawhorses, while the second has been put on the cradles. The two of us can move the completed hull around quite easily. It probably weighs around 40 kg, but we haven't measured it.

Today we worked 4 hours (so we passed the 200 hours mark), mainly to draw, cut and glue (as usual, using microfiber thickened resin) the three bottom butt blocks, In this pic you can see the various weights that we've used to press the butt blocks down.

Total work time to date: 201 hours

First ama almost done

Five hours of work today. First thing in the morning was removing the screws from the deck panel, using the soldering iron to heat the stuck ones. I then grabbed my power plane and started to fair the deck edges. Here's a pic showing the significant amount of sawdust produced

and here his the hull with the deck edges faired (not yet finished though)

We then filled the screw holes with resin

and glued the two 2-cm thick plywood pads to the deck (here's the aft one): the center hole of both pads is oversized with respect to the steel stud: it is filled with thickened resin to create a very hard support for the stud itself.

At the end of the day, here's the completed hull with the plastic hatch

Total work time to date: 195 hours.

First deck glued, and some

Here we are again. We've been more active than what appears from this blog, even if we went on a business trip of almost two weeks in the USA between late October and early November, and I visited my son in Scotland the week before.

Today we worked about 4 hours to glue the deck on the first ama. It took more than 1 kg of microfiber-thickened resin, many screws (previously lubricated) and some final fairing. Here's a pic taken at the end of the day with the milestone beer. The deck looks quite fair and flat...

Here is Cinzia spreading the glue on the inner face of the forward deck this morning

and here is the situation at lunch time, with the forward deck glued up

In the previous weeks we spent about 7 hours on other things, like fairing the round pads

or cutting the deck for the porthole

Total work time to date: 190 hours.

Round pads

If there's a simple way to cut perfectly circular shapes from thick plywood with a handheld jigsaw, I don't know it. The Seaclipper 20 pads are made of 2 cm thick plywood, and cutting through it with a noisy jigsaw, with wood dust flying all around, is very uncomfortable. So, the result is kind of miserable, the resulting shape being a polygon which only approximates a circumference... Now, those pads will be clearly visible on the boat since they'll be glued on the deck of the floats. So I decided to improve their looks, and went to my friend Franco's shop: he builds astronomical telescopes so his tolerances are way tighter than ours!

Anyway, after a treatment with his router, here's how they look like now...

Ready to glue the deck

Just one hour today, to remove screws and clamps, grind epoxy runs, and draw the two 40 cm pads ready to be cut from 2 laminated layers of 1 cm plywood. I had to heat up several screws with the soldering iron to extract them.

Here's the first ama with the deck on, ready for glue. The 12 mm steel studs are clearly visible

And here is the 2 cm thick plywood sandwich with the two circular pads ready to be cut

The morning after (Oct. 13th) I had one spare hour so I camr to the shop to cut the two pads. The laminations looks perfect

And here is the ama with the pads on (not yet glued)

Total work time to date: 180 hours

Getting ready to glue the decks

Three hours today, mostly working with resin. We double coated the inner side of the decks, and glued the butt blocks to the deck panels. We also laminated two layers of 10mm plywood from which we'll cut the two 40 cm dia circular pads. We left the glue line uncoated all around the deck panels.

Total work time to date: 179 hours

Gluing the studs in the first ama

This is a pretty delicate operation. The 12 mm steel studs are glued to the bulkheads through 15 mm holes drilled in the hefty cleats. Such holes are filled with slightly thickened resin.  Those studs will link the amas (floats) to the aka (crossbeams) Here's how we arranged the things to keep the studs steady while the glue sets...

and here's a more panoramic view showing both studs

The resin will hopefully cure overnight...

Total work time to date: 176 hours

Decking the first ama (2)

Five hours of work today, and we're still not done. We cut two of the large 3/4" (20 mm) plywood disks (pads) that will be glued to the decks to strengthen the aka fastening. Those are pretty big: for each ama hull there's a 53 cm dia pad and a 40 cm dia one. We discovered that one plywood panel is apparently not enough to cut all 20 mm pieces, so the two smaller pads will be cut from a two glued layers of 10 mm plywood.
Here we are in the middle of our jigsaw puzzle game

and here is the first of the two large pads. The center hole has a diameter of 1" (25 mm) and will be filled with thickened resin to make a high strength bond of the steel stud to the hull.

We then cut the two 20 mm thick butt blocks for the deck. Here's the forward one.

We spent more time then expected to measure, cut the bevels, and finish the blocks to fit between the beveled stringers.

The day after (Sunday 5th) I was out of town but Cinzia worked two more hours to complete some tids and bits, so it looks like we're ready to close the hull and glue everything.

Total work time to date: 174 hours

Decking the first ama (1)

A couple of days ago we spent one hour fairing the deck stringers for the 1st ama. This evening we scribed and cut the deck panels from 12 mm plywood.

Here we are at the beginning of the scribing. Some care must be taken to properly align everything, but not a big deal.

This pic shows the first panel already cut, and the second being scribed.

Total work time to date: 167 hours

1st ama interior

Five hours today. First we cut the specified 10 cm holes in the bulkheads with a cup saw. I'm not sure of what these holes are for: I think they're there to allow some air circulation. We then fitted the butt blocks to the bottom taking care to cut some bevel on the sides to avoid water pools inside. The blocks were glued over the bottom panels butts with the usual microfiber thickened resin. In the picture you can see the blocks in place with one plank each acting as a weight.

We then gave a double coat of unthickened resin to the bottom, the bulkhead faces and the butt blocks. Here's another pic showing one of the butt blocks

Total work time to date: 165 hours

Cradles done

2 more hours, and the cradles are done. I tested them under my not so light weight and they did not collapse. Anyway, here's a pic showing one of the amas rightside up.

The distance between the holes for the bolts turned out to be right on the spot, but there is indeed some twist in the hull (the top of the two bulkheads do not look not exactly parallel to each other.) Nothing alarming, but a bit disturbing. The building sequence does leave much space for such adjustements...

Total work time to date: 160 hours

Cradles

The cradles for the amas required quite some thinking. Here we are in the process of cutting the pieces, which we will assemble next time.

The second photo shows a partially assembled one (the one drawn around the aft bulkhead)

Each cradle will have 4 wheels, one at each end of the two base logs.

Total work time to date: 158 hours

Yet more fairing

4 more hours today (mostly by Cinzia) to complete fairing of the chines. Not much to show other than wood flour. Next step is going to be filling/fairing screw holes, dents and epoxy runs in preparation for fiberglassing.

Here's a view of the chine at the stem

and one at the stern, showing the sort of holes we'll have to fill and fair.

Total work time to date: 156 hours

More fairing, cradles

Oddly enough, boatbuilding is slower in summer... anyway, two hours today during which we started the cradles for the amas and did some more fairing. First thing was the building of a fairing board, using some scrap 10 mm plywood and some leftover fir. It took 20 minutes to build it from scratch. Here it is

And here's a close up of one of the ama chines after fairing with 120 grit sandpaper.

Finally, we drew the two ama cradles starting from the bulkhead outline to which we added the thickness of butt blocks and hull panels, plus some mm allowance. We made two cardboard templates. We decided to make two separate cradles, both on wheels, in order to be able to use them on both amas (remember: the ama sections are asymmetrical).

Total work time to date: 152 hours

Disassembling the "flat out" table

At this point the flat out table, i.e. the very first thing we built, is no longer necessary so we disassembled it. The two ama hulls are still light enough to be lifted and moved around by the two of us without much effort. I would estimate a weight of 30-35 kg each. Here's your truly between the two hulls.

Next thing will be the construction of cradles to put the amas rightside up to glue up the deck.

Total work time to date: 150 hours

More fairing

Only one hour today, to continue fairing the bottom edges and to round the stem/keel corner. Here they are after some coarse electric planing followed by Surforms. I shaped the first by eye and then did the second using a cardboard profile of the first.

Regarding the chines, the plans specify rounding with radii ranging from nickel to baseball sizes. Since we are very professional, here are our gauges

Total work time to date: 147 hours